<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <script type="text/javascript">
    let jsonObj ={
      "k1": "v1",
      "k2": 1,
      "k3": true,
    }
    alert(JSON.stringify(jsonObj));

  </script>
</head>
<body>

</body>
</html>